1. Field of the Invention
The invention relates to an apparatus for construction of foam blocks having specific voids into which concrete and reinforcing rods can be placed to rapidly and inexpensively form building structures. Additionally, the apparatus can be utilized for creating large blocks for use in the packaging industry.
2. Description of the Related Art
The use of foam blocks in the packaging industry is well known. Molded polystyrene blocks are used as packing material for everything from large objects such as televisions, to the smallest such as ICs. The desirability of polystyrene blocks or other foam blocks having a plurality of cylindrical voids where wall structures can be quickly made by placing reinforcing rods within the voids and then pouring concrete into them is well known as well.
U.S. Pat. No. 4,532,745, issued to Kinard on Aug. 6, 1985, discloses an improved channel apparatus for use in foam block construction. Kinard specifies the use of rectangular blocks, preferably fabricated from expanded polystyrene beads which have the additional advantage of providing a high insulating value. Further, Kinard specifies cylindrical openings having predetermined spacing and diameter but does not disclose or suggested how the openings are to be made in the block.
U.S. Pat. No. 4,249,354, issued to Wynn on Feb. 10, 1981, discloses another method for fabricating an insulated wall panel using reinforced concrete. In this disclosure, the abutting ends of each block has a semi-cylindrical channel formed in its abutting end, lined with a sleeve when the blocks are connected together. It is not disclosed as to how these semi-cylindrical channels are to be fabricated except to suggest that it is done on sight.
Still another disclosure, U.S. Pat. No. 4,038,798, issued to Sachs on Aug. 2, 1977, specifies the use of polystyrene blocks with cylindrical channels lined with cardboard inserts. In this disclosure, each foam block is molded using the cardboard inserts thereby achieving the necessary voids to hold the poured concrete and rebar.
Other attempts have been utilized to produce cylindrical holes in foam blocks that can be used in construction. Drilling has been tried with limited success, since this technique produces ragged holes and a substantial environmental problem of loose polystyrene beads and dust. Again, all these techniques attempt to produce cylindrical channels only.
None of these disclosures provide a method of obtaining foam blocks with concrete/rebar channels that can be inexpensively and accurately formed in a variety of shapes and sizes on the job site using standard commercially available polystyrene rectangular blocks.
The difficulty in cutting polystyrene foam once a block has been formed is well known in the art. Likewise, using a heating element to melt foam is similarly well known.
U.S. Pat. No. 4,641,016 is a device for forming cylindrical tunnels in foam panels once in place in walls to accommodate electrical cables or conduits. This apparatus is designed to vaporize the foam material into which an appropriate tunnel is bored. A heated bit is advanced into the foam material and as it advances into the material it vaporizes the foam by sublimation, thus creating a tunnel in which the walls are hardened as a result of the vaporized material.
U.S. Pat. No. 3,396,616 discloses an electrically heated lance slidably held in a guide for use in perforating foam plastics, and forming long holes. This apparatus is an elongated heating configuration with a narrow elongated tapered point and a body portion of the desired hole size. The body is at a sufficient temperature to melt the foam material. The apparatus is applied to foam material by forcing the body section through the foam and melting the foam as the body section passes through.
U.S. Pat. No. 3,985,996, issued to Fischer on Oct. 12, 1976, discloses an apparatus for use in cutting arbitrary shapes in foam material. This apparatus features a loop of bendable, shape-retaining, electrically conductive resistive wire. A bore hole may be cut in foam material with this apparatus by rotating the wire element in a circular pattern. Different diameters are achieved by varying the size of the loop. However, this device does not disclose or suggest a method by which a channel could be fabricated within a foam block that has an internal wall that maintains its wall integrity throughout and has uniform bore cross section.
Nothing in the prior art provides for a method and apparatus for constructing a foam block having a plurality of predetermined bores with uniform bore cross sections of varying shapes and sizes and having a closed internal wall so that concrete poured therein cannot escape.